Suction mechanism for sheet feeders



g- Z6, 3 A. BROADMEYER 1,774,315

SUCTION MECHANISM FOR SHEET FEEDERS Filed Feb. 21, 1929.

amnion I dbtomweq Patented Aug. 26, 1930 STATES earner. orrica ALBERTBROADMEYER, OF HARRISBURG, PENNSYLVANIA, ASSIGNOR TO W. O. HICKOKMANUFACTURING COIVIPANY, OF HARRISBURG, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA SUCTION MECHANISM FOR SHEET FEEDER/S Application filedFebruary 21, 1929. Serial No. 341,734.

In the feeding of paper sheets athigh speed with suction rollers, it isfound that the vacuum utilized for causing the sheets to adhere to thesuction roller does not always break with sufiicient quickness torelease the sheets from the roller and permit them to be carried onfreely.

The object of the present invention is to provide simple and effectivemeans for causing an almost instantaneous relief of the suction orvacuum as soon as communication is out off between the suction creatingmeans and the suction roller.

In the accompanying drawings:

Figure 1 is a view diagrammatic in its character of a suction feedingsystem and illustrating the preferred embodiment of the improvement inplace thereon.

Figure 2 isa detail sectional view through the suction head associatedwith the suction roller.

Figure 3 is a detail sectional view on the line 3-3 of Figure 1.

Any desired type of sheet-engaging suction rollermay be employed. Thatshown and designated 4, constitutes the subjectmatter of Letters PatentNo. 1,706,952 granted as a result of my application, Serial No. 149,471,filed Nov. 19, 1926. This suction roller is mounted on a suitabledriving shaft 5 and rotates therewith. Also mounted on a the shaft 5.but fixed against rotation is a suction head 6, having a passageway 7lead ing to the suction roller 4. The passageway 7 opens through acoupling stem 8, from which leads a conduit 9 to the intake side of anair pump 10. In the conduit 9 is a valve mechanism including a casing 11and in this casing is a ,reciprocatory plunger valve 12. The valve 12has a groove 13 and a vent port 14. The valve is operated by means of asuitable cam 15, against which rides a roller 16 journaled on anactuating arm 17. The arm 17 has a link connection 18 with the valve 12.

As is well known, when the mechanism is in operation, the rotation ofthe cam 15 causes a periodic operation of the valve 12 first, to movethe groove 13 into a position to afford communication through theconduit 9 between the air pump 10 andthe suction roller, at which timesuction through the roller causes a sheet to adhere thereto and as theroller rotates the sheet is moved by said roller. When the valve 12moves in the opposite direction communication be tween the pumpand'suction roller is'cut oif and the pump is vented to atmospherethrough the port 14 of the valve.

Uponcthe closing of the valve 12 a partial vacuum remains in the portionof the conduit 9 between the said valve and the suction roller, and as aconsequence the sheet held to the suction roller because of the vacuum,is not as quickly released as is desirable, especially where the suctionroller is operating at relatively high speed.

To overcome this, there is provided in the head 6 a vent portj19 leadingfrom the passageway 7 and opening to atmosphere through the outer sideof the head. Located over the outer end of this vent port is a lightspring flap valve comprising a freely swinging head 20 carried by ashank or stem 21 secured by a screw or other fastener 22 to the head ,6.The tendency of this valve is normally to open, but the head 20 even inits open position, is so close to the vent port that whensuction-takesplace through the passageway 7 ,the indraft of air throughthe port 19 will cause the head 20 to move down against the head 6 andthus close the port. As soon as the controlling valve 12 moves to itsclosed position, there is a reduction of vacuum inthe passageway 7 andthe spring 21 of the valve is then suflicient to raise the valve fromthe port, opening the same and permitting the entrance of air tocompletely break the vacuum not only in the passageway, but in'thesuction roller 4. Experience has demonstrated that this deviceeffectively eliminates any tendency on the part of the sheets'to remainattached to the suction roller when the pump is cutoff from the same andresults in better feeding operation of the roller.

From the foregoing, it is thought that the construction, operation andmany advantages of the herein described invention will be apparent tothose skilled in the art, and it will be understood that various changesin the size, shape, proportion and minor details of construction may beresorted to without departing from the spirit or sacrificing any of theadvantages of the invention.

What I claim is:

1. In sheet feeding apparatus, the combination with a suction feedinghead having suction ports,of means for creating suction in the head andthrough the ports, means for periodically cutting off such suction, saidsuction creating means including a vent port in addition to the suctionports, a valve for closing said port, and yielding means of sufficientstrength to open the valve when the suction is cut off and relieve thesuction through the suction ports and sufficiently weak to causethe'intake of air through the vent when suction is on to close the vent.

2. In sheet feeding apparatus, the combination with a suction feedinghead having suction ports, of means for creating suction in the head andthrough the ports, means for periodically cutting oif such suction, saidsuction creating'means including a vent port in addition to the suctionports, a valve for closing said port, and a spring carrying the valve,said spring being of sufficient strength to open the valve when thesuction is cut off and relieve the suction through the suction ports andsufficiently weak to cause the intake of air through the vent whensuction is on to close the vent.

3. In sheet feeding apparatus, the combination with a sheet feedingsuction roller, ofsuction creating means, a conduit leading from thesuction creating means to the roller and including a head associatedwith the roller and having asuction passageway with which the rollercommunicates, a valve in the conduit for permitting and cutting offcommunication through the conduit and passageway between the suctioncreating means and the roller, said head having a vent in communicationwith the passageway and opening to atmosphere, and a spring opened flapvalve on the head that closes the port when suction is in the passagewayand opens when suction is cut off by the valve.

4. In sheet feeding apparatus,the combina-- tion with a suction roller,of a head adjacent thereto and with which the roller is rotatablyassociated, said head having. a suction passageway that communicateswith the interior of the roller, and a vent port leading from thepassageway to atmosphere and a freely movable spring-opened flap valveon the head and controlling the ventport.

In testimony whereof, I afiix my signature. v

ALBERT BROADMEYER.

